1. Field of the Invention
The present invention relates to an interactive probe card design process. In particular, this invention allows for the design of customized probe cards by utilization of an automated procedure available through the Internet.
2. Description of Related Art
Individual integrated circuit devices (dies) are typically produced by creating several identical devices on a semiconductor wafer. In general, these processes are intended to create a plurality of fully functional integrated circuit devices prior to severing the individual dies from the semiconductor wafer. In practice, however, certain physical defects in the wafer itself and certain defects in the processing of the wafer inevitably lead to some of the dies being xe2x80x9cgoodxe2x80x9d (fully-functional) and some of the dies being xe2x80x9cbadxe2x80x9d (non-functional or partially functional). It is generally desirable to be able to identify which of the plurality of dies on a wafer are good dies prior to final packaging, and preferably prior to the die being severed from the wafer. To this end, a wafer xe2x80x9ctesterxe2x80x9d or xe2x80x9cprobexe2x80x9d may advantageously be employed to make a plurality of discrete pressure connections to a like plurality of discrete connection pads (bond pads) on the dies. In this manner, the semiconductor dies can be tested and exercised, prior to severing the dies from the wafer. A conventional component of a wafer tester is a xe2x80x9cprobe card.xe2x80x9d The probe card has a plurality of probe elements for effecting connections to the respective bond pads of the semiconductor dies for testing.
Historically, the manufacturing design phase for probe cards has necessarily involved significant, and often extensive and time-consuming, substantive communications between the customers and probe card manufacturers, for example, the interactions necessary to reach the desired design specifications, implementations and fabrication constraints necessary to finalize the probe card design. Although a probe card manufacturer engineer may receive several work orders at a given time, the actual design of a particular probe card cannot begin until a certain amount of customer-specific design information is provided. Preferably, actual design does not begin until all design specifications are confirmed with the customer. Next, the engineer must develop a design satisfying these specifications and again confirm the acceptability of the design with the customer.
The advent of the Internet has potentially expedited the design process by allowing probe card manufacturers to more readily communicate with their customers. In particular, websites maintained by current probe card manufacturers have enabled customers to send and confirm their design requirements via the Internet. Despite this communication advancement, an engineer must still physically design each probe card and await the respective customer approval of each design before manufacturing can begin. In order to improve upon this procedure, an on-line tool enabling customers to design their own probe cards is provided by this invention.
The present invention fulfills the need to expedite current probe card design procedure. In particular, an interactive process is provided in which customers input their probe card design requirements and receive complete design specifications for design implementation and files for verification. The collective feasibility of each set of design requirements is determined by an automated computer system and communicated to the customer. If feasible, additional software enables prospective customers to create verification packages according to their respective design specifications. These verification packages further include drawing files visually describing the final design and verification files, e.g., files confirming wafer bonding pad data. Verification packages are reviewed and modified by the customer as needed. This process then proceeds iteratively until the customer is satisfied with the final design, at which point the design specification and verification package is forwarded to a probe card manufacturer design engineer for fabrication.
In another embodiment, the present invention provides a probe card simulation in which the prospective customer can check the signal integrity of a proposed design and determine a calculated xe2x80x9cworst casexe2x80x9d signal response or decoupling behavior. In addition to verifying signal response and decoupling behavior during simulation, in another embodiment other design factors and parameters can be simulated, such as functional correctness, delay correctness, global and local signal skew (within specified groups or between all signals), cross-talk analysis (delayed, introduced or otherwise), power integrity, jitter effects, etc.
In another embodiment, an interactive simulation of probe card performance is enabled. Data on probe card performance is incorporated into an overall modeling exercise, which includes not only the probe card, but data on the device(s) under test (or DUT), as well as data on the automated test equipment.
A more complete understanding of the method and system for designing a probe card will be afforded to those skilled in the art, as well as a realization of additional advantages and objects thereof, by a consideration of the following detailed description of the preferred embodiment. Reference will be made to the appended sheets of drawings, which will first be described briefly.